Past improvement from selection: Genetic improvement of swine first began with domestication at least 5,000 years ago and perhaps as long as 10,000 years ago. Development of specific strains or so-called breeds occurred as individual small breeders applied the use of inbreeding and selection to fix or improve characteristics that would later help define lines and breeds. Such processes were con...

Every year, thousands of purebred domestic dogs are bred by registered dog breeders. Yet, little is known about the rearing environment of these dogs, or the attitudes and priorities surrounding breeding practices of these dog breeders. The objective of this study was to explore some of the factors that dog breeders consider important for stock selection, with a particular emphasis on issues re...

The modern animal biotechnologies, such as animal cloning, transgenesis, sex determina‐ tion, stem cells, designing new livestock, must be performed on animal gametes includ‐ ing sperm and oocytes, and embryos based on embryology theory. Currently, some key biotechnologies in embryology have become the most powerful tool for animal scientists and breeders to improve genetic construction of anim...

Animal societies composed of breeders and non-breeders present a challenge to evolutionary theory because it is not immediately apparent how natural selection can preserve the genes that underlie non-breeding strategies. The clownfish Amphiprion percula forms groups composed of a breeding pair and 0-4 non-breeders. Non-breeders gain neither present direct, nor present indirect benefits from the...

As central place foragers, breeding penguins are restricted in foraging range by the need to return to the colony to feed chicks. Furthermore, breeding birds must balance energetic gain from self-feeding with the costs of returning to provision young. Non-breeding birds, however, are likely to be less restricted in foraging range and lack the high energy demands of provisioning, therefore may c...